It’s not clear exactly what the red dye is doing to the birds, but it’s definitely impacting their ability to fly, which is vital to a hummingbird’s survival.

On the Happinest website, they go into more detail, citing the Cornell Lab of Ornithology, which in turn notes, “The bottom line is that ‘instant nectar’ products containing artificial coloring are at best a waste of your hard-earned money and at worst a source of disease, suffering, and premature death in hummingbirds.”